This study examined the relationship between child maltreatment, impulsivity, and deliberate self-harm in a sample of college students. Four subtypes of impulsivity (urgency, premeditation, perseverance, and sensation seeking) were examined. Results show that participants who report child maltreatment histories also report higher levels of negative affect and higher levels of impulsivity, specifically negative urgency. In addition, those who report histories of child maltreatment are more likely to endorse deliberate self-harm behaviors as an adult. Of the 4 subtypes of impulsivity, urgency was most strongly related to deliberate self-harm. Urgency, but not the other subtypes of impulsivity, mediated the relationship between child maltreatment and self-harm. The current study contributes to the understanding of the mechanisms behind deliberate self-harm behavior by suggesting that individuals with histories of child maltreatment are more likely to engage in deliberate self-harm in an attempt to quickly reduce intense negative affect.